'use strict';

function even_to_letter(collection) {
  let arr1=new Array();
  for(let i=0;i<collection.length;i++){
    if(i%2==0){
      arr1.push(collection[i]);
    }
  }
  let result=arr1.map(function(k) {
    return String.fromCharCode(97+k);   
  });
  return result;
}

module.exports = even_to_letter;
